| Expresion | Value | (map
string?
(list 1 'en "en" 2 'to "to")) | (#f #f #t #f #f #t) | (map
(lambda (x) (* 2 x))
(list 10 20 30 40)) | (20 40 60 80) | (ul
(map
(compose li
(compose b
(lambda (x)
(font-color red x))))
(list "a" "b" "c")
)
) | | | Same as above | <ul>
<li>
<b><font color = "#ff0000">a</font></b>
</li>
<li>
<b><font color = "#ff0000">b</font></b>
</li>
<li>
<b><font color = "#ff0000">c</font></b>
</li>
</ul> |
| | In the first row we map the string? predicate on a list of atoms (number, symbols, and strings). This
reveals (in terms of boolean values) which of the elements that are strings.
In the second row of the table, we map a 'multiply with 2' function on a list of numbers. The third row is more interesting. Here we map the composition of li , b , and red font coloring
on the elements a, b, and c. When passed to the HTML mirror function ul , this makes an unordered list
with red and bold items. Notice that the compose function used in the example is a higher-order function that can compose two or more functions.
The function compose from lib/general.scm is such a function.
Notice also that the HTML
mirror function ul receives a list, not a string. The fifth and final row illustrates the raw HTML output, instead of the nicer rendering of the unordered list,
which we used in the third row.
|
